Module: Sequel::Postgres::DatabaseMethods
- Included in:
- DataObjects::Postgres::DatabaseMethods, JDBC::Postgres::DatabaseMethods, Database, Swift::Postgres::DatabaseMethods
- Defined in:
- lib/sequel/adapters/shared/postgres.rb
Overview
Methods shared by Database instances that connect to PostgreSQL.
Constant Summary collapse
- EXCLUDE_SCHEMAS =
/pg_*|information_schema/i
- PREPARED_ARG_PLACEHOLDER =
LiteralString.new('$').freeze
- RE_CURRVAL_ERROR =
/currval of sequence "(.*)" is not yet defined in this session|relation "(.*)" does not exist/.freeze
- SYSTEM_TABLE_REGEXP =
/^pg|sql/.freeze
- FOREIGN_KEY_LIST_ON_DELETE_MAP =
{'a'.freeze=>:no_action, 'r'.freeze=>:restrict, 'c'.freeze=>:cascade, 'n'.freeze=>:set_null, 'd'.freeze=>:set_default}.freeze
- SELECT_CUSTOM_SEQUENCE_SQL =
SQL fragment for custom sequences (ones not created by serial primary key), Returning the schema and literal form of the sequence name, by parsing the column defaults table.
(<<-end_sql SELECT name.nspname AS "schema", CASE WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN substr(split_part(def.adsrc, '''', 2), strpos(split_part(def.adsrc, '''', 2), '.')+1) ELSE split_part(def.adsrc, '''', 2) END AS "sequence" FROM pg_class t JOIN pg_namespace name ON (t.relnamespace = name.oid) JOIN pg_attribute attr ON (t.oid = attrelid) JOIN pg_attrdef def ON (adrelid = attrelid AND adnum = attnum) JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1]) WHERE cons.contype = 'p' AND def.adsrc ~* 'nextval' end_sql ).strip.gsub(/\s+/, ' ').freeze
- SELECT_PK_SQL =
SQL fragment for determining primary key column for the given table. Only returns the first primary key if the table has a composite primary key.
(<<-end_sql SELECT pg_attribute.attname AS pk FROM pg_class, pg_attribute, pg_index, pg_namespace WHERE pg_class.oid = pg_attribute.attrelid AND pg_class.relnamespace = pg_namespace.oid AND pg_class.oid = pg_index.indrelid AND pg_index.indkey[0] = pg_attribute.attnum AND pg_index.indisprimary = 't' end_sql ).strip.gsub(/\s+/, ' ').freeze
- SELECT_SERIAL_SEQUENCE_SQL =
SQL fragment for getting sequence associated with table’s primary key, assuming it was a serial primary key column.
(<<-end_sql SELECT name.nspname AS "schema", seq.relname AS "sequence" FROM pg_class seq, pg_attribute attr, pg_depend dep, pg_namespace name, pg_constraint cons WHERE seq.oid = dep.objid AND seq.relnamespace = name.oid AND seq.relkind = 'S' AND attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid AND attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] AND cons.contype = 'p' end_sql ).strip.gsub(/\s+/, ' ').freeze
Instance Method Summary collapse
-
#commit_prepared_transaction(transaction_id) ⇒ Object
Commit an existing prepared transaction with the given transaction identifier string.
-
#create_function(name, definition, opts = {}) ⇒ Object
Creates the function in the database.
-
#create_language(name, opts = {}) ⇒ Object
Create the procedural language in the database.
-
#create_schema(name) ⇒ Object
Create a schema in the database.
-
#create_trigger(table, name, function, opts = {}) ⇒ Object
Create a trigger in the database.
-
#database_type ⇒ Object
PostgreSQL uses the :postgres database type.
-
#drop_function(name, opts = {}) ⇒ Object
Drops the function from the database.
-
#drop_language(name, opts = {}) ⇒ Object
Drops a procedural language from the database.
-
#drop_schema(name, opts = {}) ⇒ Object
Drops a schema from the database.
-
#drop_trigger(table, name, opts = {}) ⇒ Object
Drops a trigger from the database.
-
#foreign_key_list(table, opts = {}) ⇒ Object
Return full foreign key information using the pg system tables, including :name, :on_delete, :on_update, and :deferrable entries in the hashes.
-
#indexes(table, opts = {}) ⇒ Object
Use the pg_* system tables to determine indexes on a table.
-
#locks ⇒ Object
Dataset containing all current database locks.
-
#notify(channel, opts = {}) ⇒ Object
Notifies the given channel.
-
#primary_key(table, opts = {}) ⇒ Object
Return primary key for the given table.
-
#primary_key_sequence(table, opts = {}) ⇒ Object
Return the sequence providing the default for the primary key for the given table.
-
#reset_primary_key_sequence(table) ⇒ Object
Reset the primary key sequence for the given table, baseing it on the maximum current value of the table’s primary key.
-
#rollback_prepared_transaction(transaction_id) ⇒ Object
Rollback an existing prepared transaction with the given transaction identifier string.
-
#serial_primary_key_options ⇒ Object
PostgreSQL uses SERIAL psuedo-type instead of AUTOINCREMENT for managing incrementing primary keys.
-
#server_version(server = nil) ⇒ Object
The version of the PostgreSQL server, used for determining capability.
-
#supports_create_table_if_not_exists? ⇒ Boolean
PostgreSQL supports CREATE TABLE IF NOT EXISTS on 9.1+.
-
#supports_drop_table_if_exists? ⇒ Boolean
PostgreSQL supports DROP TABLE IF EXISTS.
-
#supports_prepared_transactions? ⇒ Boolean
PostgreSQL supports prepared transactions (two-phase commit) if max_prepared_transactions is greater than 0.
-
#supports_savepoints? ⇒ Boolean
PostgreSQL supports savepoints.
-
#supports_transaction_isolation_levels? ⇒ Boolean
PostgreSQL supports transaction isolation levels.
-
#supports_transactional_ddl? ⇒ Boolean
PostgreSQL supports transaction DDL statements.
-
#tables(opts = {}, &block) ⇒ Object
Array of symbols specifying table names in the current database.
-
#type_supported?(type) ⇒ Boolean
Check whether the given type name string/symbol (e.g. :hstore) is supported by the database.
-
#views(opts = {}) ⇒ Object
Array of symbols specifying view names in the current database.
Instance Method Details
#commit_prepared_transaction(transaction_id) ⇒ Object
Commit an existing prepared transaction with the given transaction identifier string.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 114 def commit_prepared_transaction(transaction_id) run("COMMIT PREPARED #{literal(transaction_id)}") end |
#create_function(name, definition, opts = {}) ⇒ Object
Creates the function in the database. Arguments:
-
name : name of the function to create
-
definition : string definition of the function, or object file for a dynamically loaded C function.
-
opts : options hash:
-
:args : function arguments, can be either a symbol or string specifying a type or an array of 1-3 elements:
-
element 1 : argument data type
-
element 2 : argument name
-
element 3 : argument mode (e.g. in, out, inout)
-
-
:behavior : Should be IMMUTABLE, STABLE, or VOLATILE. PostgreSQL assumes VOLATILE by default.
-
:cost : The estimated cost of the function, used by the query planner.
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:language : The language the function uses. SQL is the default.
-
:link_symbol : For a dynamically loaded see function, the function’s link symbol if different from the definition argument.
-
:returns : The data type returned by the function. If you are using OUT or INOUT argument modes, this is ignored. Otherwise, if this is not specified, void is used by default to specify the function is not supposed to return a value.
-
:rows : The estimated number of rows the function will return. Only use if the function returns SETOF something.
-
:security_definer : Makes the privileges of the function the same as the privileges of the user who defined the function instead of the privileges of the user who runs the function. There are security implications when doing this, see the PostgreSQL documentation.
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:set : Configuration variables to set while the function is being run, can be a hash or an array of two pairs. search_path is often used here if :security_definer is used.
-
:strict : Makes the function return NULL when any argument is NULL.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 138 def create_function(name, definition, opts={}) self << create_function_sql(name, definition, opts) end |
#create_language(name, opts = {}) ⇒ Object
Create the procedural language in the database. Arguments:
-
name : Name of the procedural language (e.g. plpgsql)
-
opts : options hash:
-
:handler : The name of a previously registered function used as a call handler for this language.
-
:replace: Replace the installed language if it already exists (on PostgreSQL 9.0+).
-
:trusted : Marks the language being created as trusted, allowing unprivileged users to create functions using this language.
-
:validator : The name of previously registered function used as a validator of functions defined in this language.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 149 def create_language(name, opts={}) self << create_language_sql(name, opts) end |
#create_schema(name) ⇒ Object
Create a schema in the database. Arguments:
-
name : Name of the schema (e.g. admin)
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# File 'lib/sequel/adapters/shared/postgres.rb', line 155 def create_schema(name) self << create_schema_sql(name) end |
#create_trigger(table, name, function, opts = {}) ⇒ Object
Create a trigger in the database. Arguments:
-
table : the table on which this trigger operates
-
name : the name of this trigger
-
function : the function to call for this trigger, which should return type trigger.
-
opts : options hash:
-
:after : Calls the trigger after execution instead of before.
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:args : An argument or array of arguments to pass to the function.
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:each_row : Calls the trigger for each row instead of for each statement.
-
:events : Can be :insert, :update, :delete, or an array of any of those. Calls the trigger whenever that type of statement is used. By default, the trigger is called for insert, update, or delete.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 169 def create_trigger(table, name, function, opts={}) self << create_trigger_sql(table, name, function, opts) end |
#database_type ⇒ Object
PostgreSQL uses the :postgres database type.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 174 def database_type :postgres end |
#drop_function(name, opts = {}) ⇒ Object
Drops the function from the database. Arguments:
-
name : name of the function to drop
-
opts : options hash:
-
:args : The arguments for the function. See create_function_sql.
-
:cascade : Drop other objects depending on this function.
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:if_exists : Don’t raise an error if the function doesn’t exist.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 184 def drop_function(name, opts={}) self << drop_function_sql(name, opts) end |
#drop_language(name, opts = {}) ⇒ Object
Drops a procedural language from the database. Arguments:
-
name : name of the procedural language to drop
-
opts : options hash:
-
:cascade : Drop other objects depending on this function.
-
:if_exists : Don’t raise an error if the function doesn’t exist.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 193 def drop_language(name, opts={}) self << drop_language_sql(name, opts) end |
#drop_schema(name, opts = {}) ⇒ Object
Drops a schema from the database. Arguments:
-
name : name of the schema to drop
-
opts : options hash:
-
:cascade : Drop all objects in this schema.
-
:if_exists : Don’t raise an error if the schema doesn’t exist.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 202 def drop_schema(name, opts={}) self << drop_schema_sql(name, opts) end |
#drop_trigger(table, name, opts = {}) ⇒ Object
Drops a trigger from the database. Arguments:
-
table : table from which to drop the trigger
-
name : name of the trigger to drop
-
opts : options hash:
-
:cascade : Drop other objects depending on this function.
-
:if_exists : Don’t raise an error if the function doesn’t exist.
-
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# File 'lib/sequel/adapters/shared/postgres.rb', line 212 def drop_trigger(table, name, opts={}) self << drop_trigger_sql(table, name, opts) end |
#foreign_key_list(table, opts = {}) ⇒ Object
Return full foreign key information using the pg system tables, including :name, :on_delete, :on_update, and :deferrable entries in the hashes.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 218 def foreign_key_list(table, opts={}) m = output_identifier_meth im = input_identifier_meth schema, table = schema_and_table(table) range = 0...32 base_ds = . where(:cl__relkind=>'r', :co__contype=>'f', :cl__relname=>im.call(table)). from(:pg_constraint___co). join(:pg_class___cl, :oid=>:conrelid) # We split the parsing into two separate queries, which are merged manually later. # This is because PostgreSQL stores both the referencing and referenced columns in # arrays, and I don't know a simple way to not create a cross product, as PostgreSQL # doesn't appear to have a function that takes an array and element and gives you # the index of that element in the array. ds = base_ds. join(:pg_attribute___att, :attrelid=>:oid, :attnum=>SQL::Function.new(:ANY, :co__conkey)). order(:co__conname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:co__conkey, [x]), x]}, 32, :att__attnum)). select(:co__conname___name, :att__attname___column, :co__confupdtype___on_update, :co__confdeltype___on_delete, SQL::BooleanExpression.new(:AND, :co__condeferrable, :co__condeferred).as(:deferrable)) ref_ds = base_ds. join(:pg_class___cl2, :oid=>:co__confrelid). join(:pg_attribute___att2, :attrelid=>:oid, :attnum=>SQL::Function.new(:ANY, :co__confkey)). order(:co__conname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:co__conkey, [x]), x]}, 32, :att2__attnum)). select(:co__conname___name, :cl2__relname___table, :att2__attname___refcolumn) # If a schema is given, we only search in that schema, and the returned :table # entry is schema qualified as well. if schema ds = ds.join(:pg_namespace___nsp, :oid=>:cl__relnamespace). where(:nsp__nspname=>im.call(schema)) ref_ds = ref_ds.join(:pg_namespace___nsp2, :oid=>:cl2__relnamespace). select_more(:nsp2__nspname___schema) end h = {} fklod_map = FOREIGN_KEY_LIST_ON_DELETE_MAP ds.each do |row| if r = h[row[:name]] r[:columns] << m.call(row[:column]) else h[row[:name]] = {:name=>m.call(row[:name]), :columns=>[m.call(row[:column])], :on_update=>fklod_map[row[:on_update]], :on_delete=>fklod_map[row[:on_delete]], :deferrable=>row[:deferrable]} end end ref_ds.each do |row| r = h[row[:name]] r[:table] ||= schema ? SQL::QualifiedIdentifier.new(m.call(row[:schema]), m.call(row[:table])) : m.call(row[:table]) r[:key] ||= [] r[:key] << m.call(row[:refcolumn]) end h.values end |
#indexes(table, opts = {}) ⇒ Object
Use the pg_* system tables to determine indexes on a table
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# File 'lib/sequel/adapters/shared/postgres.rb', line 275 def indexes(table, opts={}) m = output_identifier_meth im = input_identifier_meth schema, table = schema_and_table(table) range = 0...32 attnums = server_version >= 80100 ? SQL::Function.new(:ANY, :ind__indkey) : range.map{|x| SQL::Subscript.new(:ind__indkey, [x])} ds = . from(:pg_class___tab). join(:pg_index___ind, :indrelid=>:oid, im.call(table)=>:relname). join(:pg_class___indc, :oid=>:indexrelid). join(:pg_attribute___att, :attrelid=>:tab__oid, :attnum=>attnums). filter(:indc__relkind=>'i', :ind__indisprimary=>false, :indexprs=>nil, :indpred=>nil, :indisvalid=>true). order(:indc__relname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:ind__indkey, [x]), x]}, 32, :att__attnum)). select(:indc__relname___name, :ind__indisunique___unique, :att__attname___column) ds.join!(:pg_namespace___nsp, :oid=>:tab__relnamespace, :nspname=>schema.to_s) if schema ds.filter!(:indisready=>true, :indcheckxmin=>false) if server_version >= 80300 indexes = {} ds.each do |r| i = indexes[m.call(r[:name])] ||= {:columns=>[], :unique=>r[:unique]} i[:columns] << m.call(r[:column]) end indexes end |
#locks ⇒ Object
Dataset containing all current database locks
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# File 'lib/sequel/adapters/shared/postgres.rb', line 302 def locks dataset.from(:pg_class).join(:pg_locks, :relation=>:relfilenode).select(:pg_class__relname, Sequel::SQL::ColumnAll.new(:pg_locks)) end |
#notify(channel, opts = {}) ⇒ Object
Notifies the given channel. See the PostgreSQL NOTIFY documentation. Options:
- :payload
-
The payload string to use for the NOTIFY statement. Only supported in PostgreSQL 9.0+.
- :server
-
The server to which to send the NOTIFY statement, if the sharding support is being used.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 312 def notify(channel, opts={}) execute_ddl("NOTIFY #{channel}#{", #{literal(opts[:payload].to_s)}" if opts[:payload]}", opts) end |
#primary_key(table, opts = {}) ⇒ Object
Return primary key for the given table.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 317 def primary_key(table, opts={}) quoted_table = quote_schema_table(table) @primary_keys.fetch(quoted_table) do schema, table = schema_and_table(table) sql = "#{SELECT_PK_SQL} AND pg_class.relname = #{literal(table)}" sql << "AND pg_namespace.nspname = #{literal(schema)}" if schema @primary_keys[quoted_table] = fetch(sql).single_value end end |
#primary_key_sequence(table, opts = {}) ⇒ Object
Return the sequence providing the default for the primary key for the given table.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 328 def primary_key_sequence(table, opts={}) quoted_table = quote_schema_table(table) @primary_key_sequences.fetch(quoted_table) do schema, table = schema_and_table(table) table = literal(table) sql = "#{SELECT_SERIAL_SEQUENCE_SQL} AND seq.relname = #{table}" sql << " AND name.nspname = #{literal(schema)}" if schema unless pks = fetch(sql).single_record sql = "#{SELECT_CUSTOM_SEQUENCE_SQL} AND t.relname = #{table}" sql << " AND name.nspname = #{literal(schema)}" if schema pks = fetch(sql).single_record end @primary_key_sequences[quoted_table] = if pks literal(SQL::QualifiedIdentifier.new(pks[:schema], LiteralString.new(pks[:sequence]))) end end end |
#reset_primary_key_sequence(table) ⇒ Object
Reset the primary key sequence for the given table, baseing it on the maximum current value of the table’s primary key.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 349 def reset_primary_key_sequence(table) return unless seq = primary_key_sequence(table) pk = SQL::Identifier.new(primary_key(table)) db = self seq_ds = db.from(LiteralString.new(seq)) get{setval(seq, db[table].select{coalesce(max(pk)+seq_ds.select{:increment_by}, seq_ds.select(:min_value))}, false)} end |
#rollback_prepared_transaction(transaction_id) ⇒ Object
Rollback an existing prepared transaction with the given transaction identifier string.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 359 def rollback_prepared_transaction(transaction_id) run("ROLLBACK PREPARED #{literal(transaction_id)}") end |
#serial_primary_key_options ⇒ Object
PostgreSQL uses SERIAL psuedo-type instead of AUTOINCREMENT for managing incrementing primary keys.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 365 def {:primary_key => true, :serial => true, :type=>Integer} end |
#server_version(server = nil) ⇒ Object
The version of the PostgreSQL server, used for determining capability.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 370 def server_version(server=nil) return @server_version if @server_version @server_version = synchronize(server) do |conn| (conn.server_version rescue nil) if conn.respond_to?(:server_version) end unless @server_version @server_version = if m = /PostgreSQL (\d+)\.(\d+)(?:(?:rc\d+)|\.(\d+))?/.match(fetch('SELECT version()').single_value) (m[1].to_i * 10000) + (m[2].to_i * 100) + m[3].to_i else 0 end end warn 'Sequel no longer supports PostgreSQL <8.2, some things may not work' if @server_version < 80200 @server_version end |
#supports_create_table_if_not_exists? ⇒ Boolean
PostgreSQL supports CREATE TABLE IF NOT EXISTS on 9.1+
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# File 'lib/sequel/adapters/shared/postgres.rb', line 387 def supports_create_table_if_not_exists? server_version >= 90100 end |
#supports_drop_table_if_exists? ⇒ Boolean
PostgreSQL supports DROP TABLE IF EXISTS
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# File 'lib/sequel/adapters/shared/postgres.rb', line 392 def supports_drop_table_if_exists? true end |
#supports_prepared_transactions? ⇒ Boolean
PostgreSQL supports prepared transactions (two-phase commit) if max_prepared_transactions is greater than 0.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 398 def supports_prepared_transactions? return @supports_prepared_transactions if defined?(@supports_prepared_transactions) @supports_prepared_transactions = self['SHOW max_prepared_transactions'].get.to_i > 0 end |
#supports_savepoints? ⇒ Boolean
PostgreSQL supports savepoints
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# File 'lib/sequel/adapters/shared/postgres.rb', line 404 def supports_savepoints? true end |
#supports_transaction_isolation_levels? ⇒ Boolean
PostgreSQL supports transaction isolation levels
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# File 'lib/sequel/adapters/shared/postgres.rb', line 409 def supports_transaction_isolation_levels? true end |
#supports_transactional_ddl? ⇒ Boolean
PostgreSQL supports transaction DDL statements.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 414 def supports_transactional_ddl? true end |
#tables(opts = {}, &block) ⇒ Object
Array of symbols specifying table names in the current database. The dataset used is yielded to the block if one is provided, otherwise, an array of symbols of table names is returned.
Options:
-
:schema - The schema to search (default_schema by default)
-
:server - The server to use
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# File 'lib/sequel/adapters/shared/postgres.rb', line 425 def tables(opts={}, &block) pg_class_relname('r', opts, &block) end |
#type_supported?(type) ⇒ Boolean
Check whether the given type name string/symbol (e.g. :hstore) is supported by the database.
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# File 'lib/sequel/adapters/shared/postgres.rb', line 431 def type_supported?(type) @supported_types ||= {} @supported_types.fetch(type){@supported_types[type] = (from(:pg_type).filter(:typtype=>'b', :typname=>type.to_s).count > 0)} end |
#views(opts = {}) ⇒ Object
Array of symbols specifying view names in the current database.
Options:
-
:schema - The schema to search (default_schema by default)
-
:server - The server to use
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# File 'lib/sequel/adapters/shared/postgres.rb', line 441 def views(opts={}) pg_class_relname('v', opts) end |